Description: This is a fleshy bryozoan, which is sometimes mistaken for a tunicate or sponge. It consists of thin finger-like growths, variously branched or webbed together. When undisturbed small white zooids with a crown of tentacles emerge from all surfaces.

Habitat: Very common in the sublittoral zone in a wide range of habitats, attached to rocks or shells.

Distribution: Widespread all round the British Isles.

Similar Species: Some other species of Alcyonidium are similar and others are encrusting.

Key Identification Features:

• Thin cartilaginous branches
• Fine textured appearance with zooids which emerge when undisturbed

Distribution Map from NBN: Alcyonidium diaphanum at National Biodiversity Network mapping facility, data for UK.

iNaturalist: Alcyonidium diaphanum at iNaturalist World Species Observations database.

WoRMS: Alcyonidium diaphanum at World Register of Marine Species. Accepted name: Alcyonidium diaphanum (Hudson, 1778). AphiaID: 111597.

Classification: Biota; Animalia; Bryozoa; Gymnolaemata; Ctenostomatida; Alcyonidiina; Alcyonidioidea; Alcyonidiidae; Alcyonidium